Gamma Rays No Longer a Mystery
Jim Newman
Florence Morning News, SC (US)
_________________________
Their origins have remained a mystery for more than three decades, but technology along with Einsteinian brainstorming has put together an explanation behind the tremendous surges of energy that power short duration gamma ray bursts.
The source? The smashing together of two neutron stars, which represent the incredibly dense remains of much larger stars that collapsed and then exploded once they had exhausted their supply of nuclear fuel. The effect from such colossal compression means these stellar remnants are only about 12 miles in diameter. Their matter is so dense, however, that a teaspoon of it would weigh about 10 million tons.
Over time, the orbits governing a pair of neutron stars slowly decay and both merge in a sudden, spectacular release of energy giving birth to a short-lived gamma ray burst. The burst is channeled as a collimated beam through the poles of an intense magnetic field. A neutron star typically has a strong magnetic field because the initial collapse from its progenitor star also compressed as well as amplified the original field.
Gamma rays are found on the far left of the electromagnetic spectrum and possess the most energy. As powerful as they are, the only way to detect them is from above the Earth's atmosphere through which the gamma ray is unable to penetrate.
Gamma ray bursts were detected through happenstance back in the 1960s by U.S. military satellites on the lookout for Soviet nuclear bomb detonations, which also generate gamma radiation. But as fast as the cosmic flashes would appear, these brief, but potent surges of energy quickly vanished.
To put their power in perspective, these bursts emit more energy in 10 seconds than the sun will process during its existence. If such a discharge occur-red close enough, and was aimed in our direction, it's likely that such a barrage of radiation would strip the Earth's ozone layer and severely damage the planet's biosphere.
A good example of a "harmless" neutron star is the pulsar that lies in the heart of the Crab Nebula in Taurus, a supernova remnant of a massive star that exploded in the year 1054. This rapidly rotating object, spinning at 30 times per second, beams visible and radio emissions at regular intervals.
Scientists said this latest discovery, however, is one of the last pieces of the puzzle to the short-period gamma ray burst mystery, although it's been thought most longer duration bursts are created when a massive star collapses and forms a black hole.
Dr. Dieter Hartmann, a professor of astrophysics at Clemson University who has participated in gamma ray burst studies, said the discovery is a huge boost for high-energy astronomy and a testament toward a greater understanding of what makes the universe tick.
Jim Newman
Florence Morning News, SC (US)
_________________________
Their origins have remained a mystery for more than three decades, but technology along with Einsteinian brainstorming has put together an explanation behind the tremendous surges of energy that power short duration gamma ray bursts.
The source? The smashing together of two neutron stars, which represent the incredibly dense remains of much larger stars that collapsed and then exploded once they had exhausted their supply of nuclear fuel. The effect from such colossal compression means these stellar remnants are only about 12 miles in diameter. Their matter is so dense, however, that a teaspoon of it would weigh about 10 million tons.
Over time, the orbits governing a pair of neutron stars slowly decay and both merge in a sudden, spectacular release of energy giving birth to a short-lived gamma ray burst. The burst is channeled as a collimated beam through the poles of an intense magnetic field. A neutron star typically has a strong magnetic field because the initial collapse from its progenitor star also compressed as well as amplified the original field.
Gamma rays are found on the far left of the electromagnetic spectrum and possess the most energy. As powerful as they are, the only way to detect them is from above the Earth's atmosphere through which the gamma ray is unable to penetrate.
Gamma ray bursts were detected through happenstance back in the 1960s by U.S. military satellites on the lookout for Soviet nuclear bomb detonations, which also generate gamma radiation. But as fast as the cosmic flashes would appear, these brief, but potent surges of energy quickly vanished.
To put their power in perspective, these bursts emit more energy in 10 seconds than the sun will process during its existence. If such a discharge occur-red close enough, and was aimed in our direction, it's likely that such a barrage of radiation would strip the Earth's ozone layer and severely damage the planet's biosphere.
A good example of a "harmless" neutron star is the pulsar that lies in the heart of the Crab Nebula in Taurus, a supernova remnant of a massive star that exploded in the year 1054. This rapidly rotating object, spinning at 30 times per second, beams visible and radio emissions at regular intervals.
Scientists said this latest discovery, however, is one of the last pieces of the puzzle to the short-period gamma ray burst mystery, although it's been thought most longer duration bursts are created when a massive star collapses and forms a black hole.
Dr. Dieter Hartmann, a professor of astrophysics at Clemson University who has participated in gamma ray burst studies, said the discovery is a huge boost for high-energy astronomy and a testament toward a greater understanding of what makes the universe tick.
